Embodiments of the present invention relate to a switch module for a converter and a converter with one switch module. Such switch modules are applied in the converters so as to convert an alternating current or alternating voltage in to several voltage values in an output voltage. For this purpose, the switch module presents several power semi-conductor switches and an intermediate circuit with a capacitor. With the help of such switch module a converter can be developed. The converter can be used as rectifier and/or alternating current-converter and generally as power converter respectively.
Such a switch module and a converter comprising several switch modules are well known from DE 10 2010 046142 A1. The switch module presents two power semi-conductor switches, with which a diode is connected in series. Parallel to both the series connections a capacitor is arranged. Depending on the switching conditions of both the power semi-conductor switches the current flow can be used for charging the capacitor and/or discharging the capacitor. Thereby, an output voltage is generated at an output of the switch module is created, which is either equal to null, if the capacitor is not in the current-conducting path, it is greater than null if the capacitor was charged through a current in a first direction, or is smaller than null if the capacitor was charged through a current in an reverse second direction.
US 2012/0243282 A1 discloses a converter for high voltages. This module type and/or the partial converter is equipped for a bidirectional current flow. It presents a series connection from two power semi-conductor switches, a series switch comprising two diodes arranged parallel to it and a capacitor parallel to it. The central point of both the series connections is connected with a common converter connection. The described arrangement is provided both in an input circuit and also in an output circuit. The input circuit and the output circuit are linked with each other through a connection circuit. Through the connection circuit, the capacitor of the input circuit is connected to both the input connections through the series connection from a diode and a resistance with the assigned capacitor connection for the capacitor of the output circuit. The connection circuit presents another diode and parallel to it a power semi-conductor in a switch-branch. The diode in the switch-branch is arranged in such a way that its conducting direction conforms to the conducting direction of the other diode of the connection circuit. The arrangement as a whole presents five power semi-conductor switches and seven diodes. With this arrangement, it is possible to adjust five different voltage values between both the connections. The expenditure for the switching and the component is comparatively large.
A similar arrangement is known from EP 1497911 B1. There, in the connection circuit, instead of the series connection from the diode and the resistance, a parallel connection of a power semi-conductor switch and a diode is provided, whereby the switch-branch is dispensed with. This arrangement requires six power semi-conductor switches and six diodes.
Based on the state of the art, it can also be viewed as the object of the present invention to create a simplified switch module for use in a converter. This objective is solved through a switch module and a converter with the features given in embodiments of the present invention.